05000456/FIN-2012003-05
From kanterella
Revision as of 19:45, 20 February 2018 by StriderTol (talk | contribs) (Created page by program invented by StriderTol)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Finding | |
|---|---|
| Title | Licensees Position Regarding TS 3.6.3 Applicability to Main Steam Isolation Valves |
| Description | On May 30, 2012, with Unit 1 operating at full power, the licensee declared the Unit 1A MSIV inoperable in accordance with TS 3.7.2 based on maintenance performed on the valves actuating device to address an emergent issue. This maintenance prevented the valve from closing since it temporarily removed both the active and standby accumulators from service. The inspectors questioned why the licensee had not entered TS 3.6.3, Containment Isolation Valves, since this valve was identified in the UFSAR as a CIV meeting General Design Criteria (GDC) 57 requirements and TS 3.6.3.c specifically addressed penetration flow paths with only one CIV in a closed system. Specifically, TS 3.6.3 stated, in part: LCO [Limiting Condition for Operation] 3.6.3 - Each containment isolation valve shall be OPERABLE. APPLICABILITY: MODES 1, 2, 3, and 4 C. Note. Only applicable to penetration flow paths with only one containment isolation valve and a closed system. REQUIRED ACTION COMPLETION TIME C.1 Isolate the affected penetration flow path 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> by use of at least one closed or deactivated automatic or remote manual valve, closed manual valve, or blind flange. C.2 Verify the affected penetration flow path is Once per 31 days Isolated The inspectors interviewed and discussed their question with licensee staff and management. When evaluating TS 3.6.3 applicability prior to the maintenance activity, Operations referred to a table of CIVs listed in the TS 3.6.3 Bases section. The MSIVs were not listed in this table, and therefore Operations concluded that TS 3.6.3 was not applicable. The licensee entered the inspectors question into the CAP, and evaluated the issue in more detail by reviewing the origin of the TS 3.6.3 Bases table, re-reviewed the CLB, and conducted an independent review by corporate licensing engineers to determine if TS 3.6.3 should be applicable to the MSIV CIVs. In addition, the licensee contacted other reactor licensees to gain additional insights. The licensees position was that the original license never considered the MSIVs as applicable to the CIV TS and had never created a new requirement to do so through changes within the CLB. The licensees basis for this position was documented in IR 1375940 and, in summary, concluded that: The original listing of CIVs in TS 3.6.3 contained in NUREG-1223, TSs, Braidwood Station Unit Nos. 1 and 2, Docket Nos. STN 50-456 and STN 50-457, Appendix A to Licensee No. NPF-59, dated October 1986, did not include the MSIVs (MS001A/B/C/D) in TS Table 3.6-1, Containment Isolation Valves ; A separate TS provided the requirements for the MSIVs (TS 3.7.2) and were comparable at the time of original licensing (i.e. restore the valve to operable status within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />); The MSIVs were exempt from 10 CFR Part 50, Appendix J, C leak testing and it was the licensees position that these valves did not perform a containment isolation function; Any changes in licensing requirements during Improved Technical Specifications (ITS) conversions were addressed in the License Amendment Request (LAR) and associated responses to requests for additional information, and there was no change in the scope of TS 3.6.3 valves during this conversion; The allowances addressed by Generic Letter (GL) 91-08, Removal of Components Lists from TSs, applied to TSs prior to ITS conversion and were subsequently incorporated into Improved Standard TS as appropriate and therefore the requirements of GL 91-08 were not applicable to Improved Standard TS; With an inoperable MSIV, the safety analyses (both Loss of Coolant Accident (LOCA) and steam line break) remained valid assuming no additional failures; and The licensee discussed this issue with several other pressurized water reactor licensees and did not receive a consistent answer (some licensees would enter their applicable CIV TS and some licensees would not based on the May 30, 2012 scenario provided by the Braidwood licensee). The inspectors reviewed the licensees evaluation, plant CLB, and guidance contained in GL 91-08. GL 91-08 provided for preparing a request for a licensee to remove component lists from TS. The inspectors identified several questions associated with the licensees position and bases that were unresolved at the end of the inspection period. These questions included: The language submitted by the licensee and approved by the NRC in the CLB TS 3.6.3 contained four clarifying notes. None of these notes appeared applicable for clarifying the scope of CIVs beyond the TS word Each . Therefore, a simple reading of Each Containment Isolation Valve Shall be OPERABLE, implied that every CIV was affected unless a specific exception was made; The MSIVs were listed in the licensees UFSAR as GDC-57 valves (i.e. closed system CIVs); TS 3.6.3, Action C specifically addressed CIVs associated with a closed system; The MSIV bypass valves, main feedwater isolation valves, and auxiliary feedwater isolation valves were listed in the UFSAR as GDC-57 closed system CIVs, as well as the TS Bases table. Therefore, when questioned by the inspectors, the licensee concluded that TS 3.6.3 would apply to these valves, but could not readily explain the different treatment relative to the MSIVs; Aspects of GL 91-08, Removal of Component Lists from TSs, appeared to apply: . . . i.e. The list of containment isolation valves in the TS may not include all valves that are classified as containment isolation valves by the plant licensing basis. Generally, the FSAR [Final Safety Analysis Report] identified those valves that are classified as containment isolation valves. With this TS change, the LCO remedial actions, and surveillance requirements will apply for all valves that are classified as containment isolation valves by the plant licensing basis. . . ; . . . Finally, it would be inappropriate for a limiting condition for operation of the TS to reference the FSAR or any other document to specify those individual components to which the TS requirements apply . . .; Additionally, this guidance noted that TS requirements would apply to all valves that had been defined as CIVs in the plant licensing basis when clarifying if the TS was applicable to CIVs tested, or not, under 10 CFR 50, Appendix J, Type C testing. The inspectors sampled License Event Reports (LERs) and identified several examples in which various 10 CFR Part 50 licensees entered their TS 3.6.3, Containment Isolation Valves, TS upon the discovery of one or more inoperable MSIVs in Modes 1-4. Examples include: LER 05000261/1994-002-01, Plant Condition Outside Design Basis Due to MSIV ; LER 05000346/1983-003-00, MSIV Failed to Shut Completely Following a Reactor Trip LER 05000370/2005-005-00, Failure of Main Steam Line Isolation Valve to Close ; and LER 05000498/1988-015-00, Two MSIVs Inoperable Resulting in a Technical Violation . With respect to the licensees basis that there is already a TS LCO that applies with already a more conservative TS, (i.e. TS 3.7.2, Main Steam Isolation Valves ) the inspectors did not agree with the logic that plant SSCs can only have one applicable TS. More so, while the completion time for TS 3.7.3 is more conservative than TS 3.6.3.c (i.e. 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> vice 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />), the MSIV TS is applicable in Modes 1-3, while the CIV TS is applicable in Modes 1-4. So TS 3.7.2 is not more conservative from a Mode of applicability point of view. At the end of this inspection, the inspectors had not completed their review and final determination. This URI will remain open pending the inspectors review of the stations CLB and applicability of MSIVs to TS 3.6.3. |
| Site: | Braidwood  |
|---|---|
| Report | IR 05000456/2012003 Section 1R15 |
| Date counted | Jun 30, 2012 (2012Q2) |
| Type: | URI: |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.15 |
| Inspectors (proximate) | A Garmoe E Duncan F Ramirez J Benjamin J Coroju Sandin M Perry T Gom Perryr Ng R Walton T Go A Garmoe A Shaikh B Metrow E Duncan J Benjamin M Holmberg |
| INPO aspect | |
| ' | |
Finding - Braidwood - IR 05000456/2012003 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Finding List (Braidwood) @ 2012Q2
Self-Identified List (Braidwood)
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||